Permissions on my site

I have two problems on my site alfred.objectis.net and I hope you can help me.

One should be simple: I would like to make the "errata" folder that is visible to anonymous visitors to the site accessible to them, too. When I try to change the folder's permissions to allow that it does not seem to work. I must be doing it incorrectly but I can't see my mistake.

Second, you suggested some time ago that I add a captcha to my registration form as I was getting alot of automated registrations. I've tried to figure out how I can do that but I've not been able to do that either.

For the "errata" folder, this is because you removed the "search ZCatalog" permission at the root of your site, and Plone uses the catalog to render the home of a folder (list content). I re-enabled "search ZCatalog" for everyone, it's not a real issue since all the catalog will automatically filter out objects you don't have read permission on.

Fore the captcha, the issue is that you can't install products on Objectis (since the Zope instance is shared between hundred of sites), so you'll have to use ZMI customization of templates/scripts, the "old-school" way of doing Zope development. The good point is that unless you're facing bots specifically developed to target your site, a very simple captcha is enough.